Imaging lens

ABSTRACT

There is provided an imaging lens with excellent optical characteristics which satisfies demand of wide field of view, low-profileness and low F-number. An imaging lens comprises, in order from an object side to an image side, a first lens with positive refractive power having an object-side surface being convex in a paraxial region, a second lens with negative refractive power in a paraxial region, a third lens, a fourth lens being a double-sided aspheric lens, a fifth lens, a sixth lens having an image-side surface being concave in a paraxial region, and a seventh lens with negative refractive power having an image-side surface being concave in a paraxial region, wherein the image-side surface of the seventh lens is an aspheric surface having at least one pole point in a position off the optical axis, and predetermined conditional expressions are satisfied.

The present application is based on and claims priority of a Japanesepatent application No. 2018-154545 filed on Aug. 21, 2018, the entirecontents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an imaging lens which forms an image ofan object on a solid-state image sensor such as a CCD sensor or a C-MOSsensor used in an imaging device.

Description of the Related Art

In recent years, it becomes common that camera function is mounted invarious products, such as information terminal equipment, homeappliances, automobiles, and the like. Development of products with thecamera function will be made accordingly.

The imaging lens mounted in such equipment is required to be compact andto have high-resolution performance.

As a conventional imaging lens aiming high performance, for example, theimaging lens disclosed in Patent Document 1 below have been known.

Patent Document 1 (CN107037568A) discloses an imaging lens comprising,in order from an object side, a first lens with positive refractivepower having a convex object-side surface, a second lens with negativerefractive power, a third lens, a fourth lens, a fifth lens, a sixthlens having at least one aspheric surface, and a seventh lens beingdouble-sided aspheric lens.

SUMMARY OF THE INVENTION

However, in lens configurations disclosed in the Patent Document 1, whenwide field of view, low-profileness and low F-number are to be realized,it is very difficult to correct aberrations at a peripheral area, andexcellent optical performance can not be obtained.

The present invention has been made in view of the above-describedproblems, and an object of the present invention is to provide animaging lens with high resolution which satisfies demand of the widefield of view, the low-profileness and the low F-number in well balanceand excellently corrects aberrations.

Regarding terms used in the present invention, “a convex surface”, “aconcave surface” or “a plane surface” of lens surfaces implies that ashape of the lens surface in a paraxial region (near the optical axis).“Refractive power” implies the refractive power in a paraxial region. “Apole point” implies an off-axial point on an aspheric surface at which atangential plane intersects the optical axis perpendicularly. “A totaltrack length” is defined as a distance along the optical axis from anobject-side surface of an optical element located closest to the objectto an image plane. “The total track length” and “a back focus” is adistance obtained when thickness of an IR cut filter or a cover glasswhich may be arranged between the imaging lens and the image plane isconverted into an air-converted distance.

An imaging lens according to the present invention comprises, in orderfrom an object side to an image side, a first lens with positiverefractive power having an object-side surface being convex in aparaxial region, a second lens with negative refractive power in aparaxial region, a third lens, a fourth lens being a double-sidedaspheric lens, a fifth lens, a sixth lens having an image-side surfacebeing concave in a paraxial region, and a seventh lens with negativerefractive power having an image-side surface being concave in aparaxial region, wherein the image-side surface of the seventh lens isan aspheric surface having at least one pole point in a position off theoptical axis.

According to the imaging lens having the above-described configuration,the first lens properly corrects spherical aberration and distortion byhaving the object-side surface being convex in the paraxial region. Thesecond lens properly corrects the spherical aberration, chromaticaberration and the distortion. The third lens properly correctsastigmatism and the distortion. The fourth lens properly correctsaberrations at a peripheral area by the aspheric surfaces on both sides.The fifth lens properly corrects field curvature and the distortion. Thesixth lens properly corrects coma aberration, the astigmatism, the fieldcurvature and the distortion.

The seventh lens properly corrects the chromatic aberration, theastigmatism, the field curvature and the distortion. Furthermore, animage-side surface of the seventh lens is concave in a paraxial regionand is formed as an aspheric surface having at least one pole point in aposition off the optical axis. Therefore, the field curvature and thedistortion can be properly corrected and a light ray incident angle toan image sensor can be properly controlled.

According to the imaging lens having the above-described configuration,it is preferable that an image-side surface of the first lens is concavein a paraxial region.

When the image-side surface of the first lens is concave in a paraxialregion, the astigmatism and the distortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that an object-side surface of the third lens is convexin a paraxial region.

When the object-side surface of the third lens is convex in a paraxialregion, the astigmatism and the distortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the third lens is formed in a meniscus shape in aparaxial region.

When the third lens is formed in a meniscus shape in a paraxial region,the astigmatism and the distortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the fourth lens has an object-side surface and animage-side surface which are plane in a paraxial region.

When the fourth lens has the object-side surface and the image-sidesurface which are plane in a paraxial region, the astigmatism, the fieldcurvature and the distortion at the peripheral area can be properlycorrected by the aspheric surfaces on both sides without affectingrefractive power of the overall optical system of the imaging lens.

According to the imaging lens having the above-described configuration,it is preferable that an image-side surface of the fifth lens is convexin a paraxial region.

When the image-side surface of the fifth lens is convex in a paraxialregion, the field curvature and the distortion can be properlycorrected.

According to the imaging lens having the above-described configuration,it is preferable that an object-side surface of the seventh lens isconvex in a paraxial region.

When the object-side surface of the seventh lens is convex in a paraxialregion, the astigmatism and the distortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (1) issatisfied:

10.00<vd2<29.00  (1)

wherevd2: an abbe number at d-ray of the second lens.

The conditional expression (1) defines an appropriate range of the abbenumber at d-ray of the second lens. By satisfying the conditionalexpression (1), the chromatic aberration can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (2) issatisfied:

1.80<vd3/vd5<4.00  (2)

wherevd3: an abbe number at d-ray of the third lens, andvd5: an abbe number at d-ray of the fifth lens.

The conditional expression (2) defines an appropriate range of each ofthe abbe number at d-ray of the third lens and the abbe number at d-rayof the fifth lens. By satisfying the conditional expression (2), thechromatic aberration can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (3) issatisfied:

0.10<(T5/TTL)×100<0.40  (3)

whereT5: a distance along the optical axis from an image-side surface of thefifth lens to an object-side surface of the sixth lens, andTTL: a total track length.

The conditional expression (3) defines an appropriate range of adistance along the optical axis between the fifth lens and the sixthlens. By satisfying the conditional expression (3), the coma aberrationcan be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (4) issatisfied:

10.00<vd4<29.00  (4)

wherevd4: an abbe number at d-ray of the fourth lens.

The conditional expression (4) defines an appropriate range of the abbenumber at d-ray of the fourth lens. By satisfying the conditionalexpression (4), the chromatic aberration can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (5) issatisfied:

0.60<vd2/vd5<1.40  (5)

wherevd2: an abbe number at d-ray of the second lens, andvd5: an abbe number at d-ray of the fifth lens.

The conditional expression (5) defines an appropriate range of each ofthe abbe number at d-ray of the second lens and the abbe number at d-rayof the fifth lens. By satisfying the conditional expression (5), thechromatic aberration can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (6) issatisfied:

0.60<vd3/vd6<1.40  (6)

wherevd3: an abbe number at d-ray of the third lens, andvd6: an abbe number at d-ray of the sixth lens.

The conditional expression (6) defines an appropriate range of each ofthe abbe number at d-ray of the third lens and the abbe number at d-rayof the sixth lens. By satisfying the conditional expression (6), thechromatic aberration can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (7) issatisfied:

−2.30<(D2/f2)×100<−0.50  (7)

whereD2: a thickness along the optical axis of the second lens, andf2: a focal length of the second lens.

The conditional expression (7) defines an appropriate range of thethickness along the optical axis of the second lens. When a value isbelow the upper limit of the conditional expression (7), the thicknessalong the optical axis of the second lens is prevented from being toosmall, and formability of the lens becomes excellent. On the other hand,when the value is above the lower limit of the conditional expression(7), the thickness along the optical axis of the second lens issuppressed from being too large, and air gaps on the object side and theimage side of the second lens can be easily secured. As a result, thelow-profileness can be achieved. Furthermore, by satisfying theconditional expression (7), the astigmatism and the distortion can beproperly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (8) issatisfied:

0.30<(D5/|f5|)×100<6.50  (8)

whereD5: a thickness along the optical axis of the fifth lens, andf5: a focal length of the fifth lens.

The conditional expression (8) defines an appropriate range of thethickness along the optical axis of the fifth lens. When a value isbelow the upper limit of the conditional expression (8), the thicknessalong the optical axis of the fifth lens is suppressed from being toolarge, and air gaps on the object side and the image side of the fifthlens can be easily secured. As a result, the low-profileness can beachieved. On the other hand, when the value is above the lower limit ofthe conditional expression (8), the thickness along the optical axis ofthe fifth lens is prevented from being too small, and formability of thelens becomes excellent. Furthermore, by satisfying the conditionalexpression (8), the astigmatism can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (9) issatisfied:

1.00<(T3/TTL)×100<4.00  (9)

whereT3: a distance along the optical axis from an image-side surface of thethird lens to an object-side surface of the fourth lens, andTTL: a total track length.

The conditional expression (9) defines an appropriate range of adistance along the optical axis between the third lens and the fourthlens. By satisfying the conditional expression (9), the astigmatism andthe distortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (10) issatisfied:

0.10<|f3/f5|<2.10  (10)

wheref3: a focal length of the third lens, andf5: a focal length of the fifth lens.

The conditional expression (10) defines an appropriate range of each ofrefractive powers of the third lens and the fifth lens. By satisfyingthe conditional expression (10), the coma aberration, the astigmatismand the distortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (11) issatisfied:

1.55<|f3/f7|<12.50  (11)

wheref3: a focal length of the third lens, andf7: a focal length of the seventh lens.

The conditional expression (11) defines an appropriate range of each ofrefractive powers of the third lens and the seventh lens. By satisfyingthe conditional expression (11), the coma aberration, the astigmatismand the distortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (12) issatisfied:

0.50<r2/f<2.10  (12)

wherer2: a paraxial curvature radius of an image-side surface of the firstlens, andf: a focal length of the overall optical system of the imaging lens.

The conditional expression (12) defines an appropriate range of theparaxial curvature radius of the image-side surface of the first lens.When a value is below the upper limit of the conditional expression(12), the astigmatism can be properly corrected. On the other hand, whenthe value is above the lower limit of the conditional expression (12),the spherical aberration can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (13) issatisfied:

−8.50<r10/f<−0.70  (13)

wherer10: a paraxial curvature radius of an image-side surface of the fifthlens, andf: a focal length of the overall optical system of the imaging lens.

The conditional expression (13) defines an appropriate range of theparaxial curvature radius of the image-side surface of the fifth lens.When a value is below the upper limit of the conditional expression(13), the field curvature can be properly corrected. On the other hand,when the value is above the lower limit of the conditional expression(13), the astigmatism and the distortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (14) issatisfied:

0.30<r13/f<1.55  (14)

wherer13: a paraxial curvature radius of an object-side surface of theseventh lens, andf: a focal length of the overall optical system of the imaging lens.

The conditional expression (14) defines an appropriate range of theparaxial curvature radius of the object-side surface of the seventhlens. When a value is below the upper limit of the conditionalexpression (14), the field curvature can be properly corrected. On theother hand, when the value is above the lower limit of the conditionalexpression (14), the astigmatism and the distortion can be properlycorrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (15) issatisfied:

1.15<r5/f<6.70  (15)

wherer5: a paraxial curvature radius of an object-side surface of the thirdlens, andf: a focal length of the overall optical system of the imaging lens.

The conditional expression (15) defines an appropriate range of theparaxial curvature radius of the object-side surface of the third lens.By satisfying the conditional expression (15), the astigmatism and thedistortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (16) issatisfied:

0.15<r14/f<0.55  (16)

wherer14: a paraxial curvature radius of an image-side surface of the seventhlens, andf: a focal length of the overall optical system of the imaging lens.

The conditional expression (16) defines an appropriate range of theparaxial curvature radius of the image-side surface of the seventh lens.By satisfying the conditional expression (16), the astigmatism, thefield curvature and the distortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the third lens and the fourth lens have positivecomposite refractive power in a paraxial region, and more preferablethat the following conditional expression (17) is satisfied:

2.50<f34/f<14.00  (17)

wheref34: a composite focal length of the third lens and the fourth lens, andf: the focal length of the overall optical system of the imaging lens.

When the composite refractive power of the third lens and the fourthlens is positive, it is favorable for reducing a profile. Theconditional expression (17) defines an appropriate range of thecomposite refractive power of the third lens and the fourth lens. When avalue is below the upper limit of the conditional expression (17), thepositive composite refractive power of the third lens and the fourthlens becomes appropriate, and the low-profileness can be achieved. Onthe other hand, when the value is above the lower limit of theconditional expression (17), the astigmatism, the field curvature andthe distortion can be properly corrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (18) issatisfied:

0.50<(D3/f3)×100<4.50  (18)

whereD3: a thickness along the optical axis of the third lens, andf3: a focal length of the third lens.

The conditional expression (18) defines an appropriate range of thethickness along the optical axis of the third lens. When a value isbelow the upper limit of the conditional expression (18), the thicknessalong the optical axis of the third lens is suppressed from being toolarge, and air gaps on the object side and the image side of the thirdlens can be easily secured. As a result, the low-profileness can berealized. On the other hand, when the value is above the lower limit ofthe conditional expression (18), the thickness along the optical axis ofthe third lens is prevented from being too small, and the formability ofthe lens becomes excellent. Furthermore, by satisfying the conditionalexpression (18), the astigmatism and the distortion can be properlycorrected.

According to the imaging lens having the above-described configuration,it is preferable that the following conditional expression (19) issatisfied:

TTL/EPd≤2.10  (19)

whereEPd: an entrance pupil diameter, andTTL: a total track length.

The conditional expression (19) defines relationship between the totaltrack length and the entrance pupil diameter. By satisfying theconditional expression (19), the total track length can be shortened,decrease in light quantity at the peripheral area can be suppressed andan image having sufficient brightness from a center to a peripheral areacan be obtained.

Effect of Invention

According to the present invention, there can be provided an imaginglens with high resolution which satisfies demand of the wide field ofview, the low-profileness and the low F-number in well balance, andproperly corrects aberrations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing an imaging lens in Example 1according to the present invention;

FIG. 2 shows spherical aberration, astigmatism, and distortion of theimaging lens in Example 1 according to the present invention;

FIG. 3 is a schematic view showing an imaging lens in Example 2according to the present invention;

FIG. 4 shows spherical aberration, astigmatism, and distortion of theimaging lens in Example 2 according to the present invention;

FIG. 5 is a schematic view showing an imaging lens in Example 3according to the present invention;

FIG. 6 shows spherical aberration, astigmatism, and distortion of theimaging lens in Example 3 according to the present invention;

FIG. 7 is a schematic view showing an imaging lens in Example 4according to the present invention;

FIG. 8 shows spherical aberration, astigmatism, and distortion of theimaging lens in Example 4 according to the present invention;

FIG. 9 is a schematic view showing an imaging lens in Example 5according to the present invention;

FIG. 10 shows spherical aberration, astigmatism, and distortion of theimaging lens in Example 5 according to the present invention;

FIG. 11 is a schematic view showing an imaging lens in Example 6according to the present invention; and

FIG. 12 shows spherical aberration, astigmatism, and distortion of theimaging lens in Example 6 according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, the preferred embodiments of the present invention will bedescribed in detail referring to the accompanying drawings.

FIGS. 1, 3, 5, 7, 9 and 11 are schematic views of the imaging lenses inExamples 1 to 6 according to the embodiments of the present invention,respectively.

As shown in FIG. 1, the imaging lens according to the present embodimentcomprises, in order from an object side to an image side, a first lensL1 with positive refractive power having an object-side surface beingconvex in a paraxial region (near the optical axis X), a second lens L2with negative refractive power in a paraxial region (near the opticalaxis X), a third lens L3, a fourth lens L4 being a double-sided asphericlens, a fifth lens L5, a sixth lens L6 having an image-side surfacebeing concave in a paraxial region (near the optical axis X), and aseventh lens L7 with negative refractive power having an image-sidesurface being concave in a paraxial region (near the optical axis X),wherein the image-side surface of the seventh lens L7 is an asphericsurface having at least one pole point in a position off the opticalaxis X.

A filter IR such as an IR cut filter and a cover glass are arrangedbetween the seventh lens L7 and an image plane IMG (namely, the imageplane of an image sensor). The filter IR is omissible.

By arranging an aperture stop ST on the object side of the first lensL1, correction of aberrations and control of an incident angle of thelight ray of high image height to an image sensor become facilitated.

The first lens L1 has the positive refractive power and is formed in ameniscus shape having an object-side surface being convex and animage-side surface being concave in a paraxial region (near the opticalaxis X). Therefore, spherical aberration, astigmatism and distortion canbe properly corrected.

The second lens L2 has the negative refractive power and is formed in ameniscus shape having an object-side surface being convex and animage-side surface being concave in a paraxial region (near the opticalaxis X). Therefore, the spherical aberration, chromatic aberration, theastigmatism and the distortion can be properly corrected.

The third lens L3 has positive refractive power and is formed in ameniscus shape having an object-side surface being convex and animage-side surface being concave in a paraxial region (near the opticalaxis X). Therefore, the astigmatism and the distortion can be properlycorrected.

The third lens L3 may be formed in a biconvex shape having theobject-side surface being convex and the image-side surface being convexin a paraxial region (near the optical axis X) as in the Examples 2, 3and 4 shown in FIGS. 3, 5 and 7. In this case, the positive refractivepower on the both sides are favorable for reducing a profile.Furthermore, when the both-side surfaces are convex, a curvature issuppressed from being large, and sensitivity to a manufacturing errorcan be reduced.

The fourth lens L4 is formed in a shape having an object-side surfaceand an image-side surface which are plane in a paraxial region (near theoptical axis X), and substantially has no refractive power in a paraxialregion. Therefore, the astigmatism, the field curvature and thedistortion at a peripheral area can be properly corrected by asphericsurfaces on both sides without affecting refractive power of the overalloptical system of the imaging lens.

The fifth lens L5 has positive refractive power and is formed in ameniscus shape having an object-side surface being concave and animage-side surface being convex in a paraxial region (near the opticalaxis X). Therefore, a light ray incident angle to the fifth lens L5becomes appropriate, and the astigmatism, field curvature and thedistortion can be properly corrected.

The fifth lens L5 may have negative refractive power as in the Examples3 and 4 shown in FIGS. 5 and 7. In this case, it is favorable forcorrecting the chromatic aberration. Furthermore, a shape of the fifthlens L5 may be a biconvex shape having the object-side surface beingconvex and the image-side surface being convex in a paraxial region(near the optical axis X) as in the Examples 5 and 6 shown in FIGS. 9and 11. In this case, the positive refractive power on both sides arefavorable for reducing the profile. When the both-side surfaces areconvex, a curvature is suppressed from being large, and sensitivity to amanufacturing error can be reduced.

The sixth lens L6 has negative refractive power and is formed in ameniscus shape having an object-side surface being convex and animage-side surface being concave in a paraxial region (near the opticalaxis X). Therefore, coma aberration, the astigmatism, the fieldcurvature and the distortion can be properly corrected.

The sixth lens L6 may have positive refractive power as in the Examples3, 4, 5 and 6 shown in FIGS. 5, 7, 9 and 11. In this case, it isfavorable for reducing the profile.

Furthermore, the object-side surface and the image-side surface of thesixth lens L6 are formed as aspheric surfaces having at least one polepoint in a position off the optical axis X. Therefore, the fieldcurvature and the distortion can be properly corrected.

The seventh lens L7 has negative refractive power and is formed in ameniscus shape having an object-side surface being convex and theimage-side surface being concave in a paraxial region (near the opticalaxis X). Therefore, the chromatic aberration, the astigmatism, the fieldcurvature and the distortion can be properly corrected.

Furthermore, the object-side surface and the image-side surface of theseventh lens L7 are formed as aspheric surfaces having at least one polepoint in a position off the optical axis X. Therefore, the fieldcurvature and the distortion can be properly corrected, and a light rayincident angle to the image sensor can be appropriately controlled.

Regarding the imaging lens according to the present embodiments, it ispreferable that all lenses of the first lens L1 to the seventh lens L7are single lenses. Configuration only with the single lenses canfrequently use the aspheric surfaces. In the present embodiments, alllens surfaces are formed as appropriate aspheric surfaces, and theaberrations are favorably corrected. Furthermore, in comparison with thecase in which a cemented lens is used, workload is reduced, andmanufacturing in low cost becomes possible.

Furthermore, the imaging lens according to the present embodiments makesmanufacturing facilitated by using a plastic material for all of thelenses, and mass production in a low cost can be realized.

The material applied to the lens is not limited to the plastic material.By using glass material, further high performance may be aimed. It ispreferable that all of lens-surfaces are formed as aspheric surfaces,however, spherical surfaces easy to be manufactured may be adopted inaccordance with required performance.

The imaging lens according to the present embodiments shows preferableeffect by satisfying the following conditional expressions (1) to (19).

10.00<vd2<29.00  (1)

1.80<vd3/vd5<4.00  (2)

0.10<(T5/TTL)×100<0.40  (3)

10.00<vd4<29.00  (4)

0.60<vd2/vd5<1.40  (5)

0.60<vd3/vd6<1.40  (6)

−2.30<(D2/f2)×100<−0.50  (7)

0.30<(D5/|f5|)×100<6.50  (8)

1.00<(T3/TTL)×100<4.00  (9)

0.10<|f3/f5|<2.10  (10)

1.55<|f3/f7|<12.50  (11)

0.50<r2/f<2.10  (12)

−8.50<r10/f<−0.70  (13)

0.30<r13/f<1.55  (14)

1.15<r5/f<6.70  (15)

0.15<r14/f<0.55  (16)

2.50<f34/f<14.00  (17)

0.50<(D3/f3)×100<4.50  (18)

TTL/EPd≤2.10  (19)

wherevd2: an abbe number at d-ray of the second lens L2,vd3: an abbe number at d-ray of the third lens L3,vd4: an abbe number at d-ray of the fourth lens L4,vd5: an abbe number at d-ray of the fifth lens L5,vd6: an abbe number at d-ray of the sixth lens L6,D2: a thickness along the optical axis X of the second lens L2,D3: a thickness along the optical axis X of the third lens L3,D5: a thickness along the optical axis X of the fifth lens L5,T3: a distance along the optical axis X from an image-side surface ofthe third lens L3 to an object-side surface of the fourth lens L4,T5: a distance along the optical axis X from an image-side surface ofthe fifth lens L5 to an object-side surface of the sixth lens L6,TTL: a total track length,EPd: an entrance pupil diameter,f: a focal length of the overall optical system of the imaging lens,f2: a focal length of the second lens L2,f3: a focal length of the third lens L3,f5: a focal length of the fifth lens L5,f7: a focal length of the seventh lens L7,f34: a composite focal length of the third lens L3 and the fourth lensL4,r2: a paraxial curvature radius of an image-side surface of the firstlens L1,r5: a paraxial curvature radius of an object-side surface of the thirdlens L3,r10: a paraxial curvature radius of an image-side surface of the fifthlens L5,r13: a paraxial curvature radius of an object-side surface of theseventh lens L7, andr14: a paraxial curvature radius of an image-side surface of the seventhlens L7.

It is not necessary to satisfy the above all conditional expressions,and by satisfying the conditional expression individually, operationaladvantage corresponding to each conditional expression can be obtained.

The imaging lens according to the present embodiments shows furtherpreferable effect by satisfying the following conditional expressions(1a) to (19a).

15.00<vd2<24.00  (1a)

2.30<vd3/vd5<3.40  (2a)

0.16<(T5/TTL)×100<0.30  (3a)

14.50<vd4<24.50  (4a)

0.80<vd2/vd5<1.20  (5a)

0.80<vd3/vd6<1.20  (6a)

−2.10<(D2/f2)×100<−0.70  (7a)

0.40<(D5/|f5|)×100<5.50  (8a)

1.35<(T3/TTL)×100<3.50  (9a)

0.20<|f3/f5|<1.75  (10a)

2.20<|f3/f7|<10.50  (11a)

0.80<r2/f<1.70  (12a)

−7.00<r10/f<−0.85  (13a)

0.45<r13/f<1.25  (14a)

1.40<r5/f<5.90  (15a)

0.20<r14/f<0.45  (16a)

3.00<f34/f<12.50  (17a)

0.80<(D3/f3)×100<3.50  (18a)

TTL/EPd≤2.00  (19a)

The signs in the above conditional expressions have the same meanings asthose in the paragraph before the preceding paragraph.

In this embodiment, the aspheric shapes of the aspheric surfaces of thelens are expressed by Equation 1, where Z denotes an axis in the opticalaxis direction, H denotes a height perpendicular to the optical axis, Rdenotes paraxial curvature radius, k denotes a conic constant, and A4,A6, A8, A10, A12, A14, A16, A18 and A20 denote aspheric surfacecoefficients.

$\begin{matrix}{Z = {\frac{\frac{H^{2}}{R}}{1 + \sqrt{1 - {\left( {K + 1} \right)\frac{H^{2}}{R}}}} + {A_{4}H^{4}} + {A_{6}H^{6}} + {A_{8}H^{8}} + {A_{10}H^{10}} + {A_{12}H^{12}} + {A_{14}H^{14}} + {A_{16}H^{16}} + {A_{18}H^{18}} + {A_{20}H^{20}}}} & \left\lbrack {{Equation}\mspace{20mu} 1} \right\rbrack\end{matrix}$

Next, examples of the imaging lens according to this embodiment will beexplained. In each example, f denotes the focal length of the overalloptical system of the imaging lens, Fno denotes an F-number, ω denotes ahalf field of view, ih denotes a maximum image height, and TTL denotes atotal track length. Additionally, i denotes surface number counted fromthe object side, r denotes the paraxial curvature radius, d denotes thedistance of lenses along the optical axis (surface distance), Nd denotesa refractive index at d-ray (reference wavelength), and vd denotes anabbe number at d-ray. As for aspheric surfaces, an asterisk (*) is addedafter surface number i.

EXAMPLE 1

The basic lens data is shown below in Table 1.

TABLE 1 Example1 Unit mm f = 5.60 Fno = 1.50

ih = 4.60 TTL = 6.64 Surface Data i r d (Object) Infinity Infinity Nd vd 1 (Stop) Infinity −0.7981  2*  2.2531  1.0182 1.544

 3*  7.8504  0.1236  4*  4.4668  0.2700 1.571 19.48 (vd2)  5*  3.0043 0.4569  6*  9.2344  0.4975 1.535 55.66 (vd3)  7*  84.4876  0.1950  8*Infinity  0.4138 1.544 55.88 (vd4)  9* Infinity  0.4501 10* −14.3125

1.671 19.48 (vd5) 11*  −5.8088  0.0150 12*  6.1282  0.5891 1.544 55.86(vd6) 13*  5.1113  0.4379 14*  5.5306  0.5276 1.535 55.66 (vd7) 15* 2.0364  0.5756 18 Infinity  0.2100 1.517

19 Infinity  0.3167 Image Plane Constiluent Lens Data Lens Start SurfaceFocal Length Composite Focal Length Entrance pupil diameter 1  2  5.456f34 19.341 EPd 3.735 2  4 −14.762 3  6

4  8 Infinity 5 10  14.150 6 12 −71.113 7 14

Aspheric Surface Data Second Surface Third Surface Fourth Surface FifthSurface Sixth Surface Seventh Surface Eighth Surface k  0.000000E+00 0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00 −6.443085E+01−1.000000E+00 A4 −4.367540E−03 −3.974717E−02 −8.887080E−02 −5.180028E−02−7.265314E−03 −4.531455E−02 −6.400356E−02 A6  1.393044E−02  2.514026E−02 7.831744E−02  2.509294E−02 −6.885583E−02  5.573786E−02  5.790909E−02 A8−2.243510E−02 −6.520461E−03 −7.213236E−02  6.556548E−02  2.207184E−01−1.473832E−01 −1.355172E−01 A10

 2.705888E−04  8.804490E−02 −1.909733E−01 −4.531016E−01

 2.107113E−01 A12 −1.149797E−02 −2.920434E−03 −8.787910E−02 2.824872E−01

−2.004551E−01 −2.019367E−01 A14  3.699396E−03  3.682821E−03

−2.535224E−01 −4.480192E−01  1.160023E−01  1.194048E−01 A16

 1.369872E−01  2.144818E−01 −3.976641E−02 −4.151239E−02 A18 4.824105E−05  4.088739E−04  4.519771E−03 −4.078733E−02

 7.408914E−03  7.746142E−03 A20 −7.320725E−07 −3.579640E−05−3.919532E−04  5.146835E−03  6.456665E−03 −5.816295E−04 −5.993402E−04Ninth Surface Tenth Surface Eleventh Surface Twelth Surface ThirteenthSurface Fourteenth Surface Fifteenth Surface k

 0.000000E+00 −4.800721E+01  1.153285E+00  0.000000E+00 −1.450000E+01−7.054468E+00 A4 −4.686552E−02  1.293943E−02  8.747313E−02  9.994894E−02−1.483940E−02 −1.208908E−01 −6.545877E−02 A6

 4.235401E−02

−1.451254E−01  1.234993E−03

 1.930303E−02 A8

 3.538552E−02  9.888735E−02

−5.887013E−03 −4.989518E−03 A10

 7.295393E−02 −1.016424E−02 −4.841219E−02

 1.068142E−03 A12 −5.129563E−02 −3.472619E−02  1.965641E−03 1.613867E−02 −8.382609E−04 −1.079357E−04 −1.605566E−04 A14

 9.791381E−03 −2.558174E−04

 1.356720E−04

 1.538260E−05 A16

 1.813316E−05

−1.337151E−05 −5.216867E−07 −8.873892E−07 A18

 9.632253E−05 −3.704225E−07

 7.268158E−07

 2.814583E−08 A20 −4.917261E−05  8.042248E−07

 1.052509E−06 −1.657857E−08 −2.235181E−10 −3.782425E−10

indicates data missing or illegible when filed

The imaging lens in Example 1 satisfies conditional expressions (1) to(19) as shown in Table 7.

FIG. 2 shows spherical aberration (mm), astigmatism (mm), and distortion(%) of the imaging lens in Example 1. The spherical aberration diagramshows the amount of aberration at each wavelength of F-ray (486 nm),d-ray (588 nm), and C-ray (656 nm). The astigmatism diagram shows theamount of aberration at d-ray on a sagittal image surface S (solid line)and on tangential image surface T (broken line), respectively (same asFIGS. 4, 6, 8, 10 and 12). As shown in FIG. 2, each aberration iscorrected excellently.

EXAMPLE 2

The basic lens data is shown below in Table 2.

TABLE 2 Example2 Unit mm f = 5.60 Fno = 1.50

ih = 4.60 TTL = 6.63 Surface Data i r d (Object) Infinity Infinity Nd vd 1 (Stop) Infinity

 2*

0.9826 1.544 55.86 (vd1)  3*   7.5250 0.1602  4*   4.0813 0.2700 1.67119.48 (vd2)  5*

0.4713  6*   10.5356 0.4972 1.535 55.66 (vd3)  7* −1427.7550 0.1831  8*Infinity 0.4000

19.48 (vd4)  9* Infinity 0.4741 10*  −13.4127 0.5806 1.671 19.48 (vd5)11*   −5.8934 0.0150 12*

1.544 55.86 (vd6) 13*   5.1877 0.4345 14*   5.6973 0.5390 1.535 55.66(vd7) 15*   2.0279

18 Infinity 0.2100 1.517 64.20 19 Infinity 0.3116 Image PlaneConstituent Lens Data Lens Start Surface Focal Length Composite FocalLength Entrance pupil diameter 1  2

f34 19.558 EPd 3.734 2  4 −17.234 3  6  19.558 4  8 Infinity 5 10 15.187 6 12 −87.423 7 14  −6.205 Aspheric Surface Data Second SurfaceThird Surface Fourth Surface Fifth Surface Sixth Surface Seventh SurfaceEighth Surface k  0.000000E+00  0.000000E+00  0.000000E+00

 0.000000E+00 −6.443085E+01  0.000000E+00 A4  1.479570E−03 −3.716529E−02

−9.225216E−03 −5.787148E−02 −8.059018E−02 A6  4.803357E−03  3.333594E−02 6.637939E−02 −2.925483E−02

 9.750335E−02 A8

−3.324379E−02 −7.344070E−02  2.017549E−01

−1.631984E−01 −1.878075E−01 A10  1.083384E−02

−4.201595E−01

 2.095499E−01  2.558189E−01 A12 −7.170524E−03 −2.342968E−02−1.012247E−01  5.337556E−01  5.304060E−01 −1.759530E−01 −2.226241E−01A14  2.869980E−03  1.154267E−02

 9.179297E−02  1.214275E−01 A16 −6.896533E−04

−2.408708E−02

−3.949215E−02 A18  9.171359E−05  6.046082E−04

−5.891170E−02 −5.521946E−02  4.547200E−03  6.969036E−03 A20

−4.410846E−05

 6.316130E−03

−5.140519E−04 Ninth Surface Tenth Surface Eleventh Surface TwelthSurface Thirteenth Surface Fourteenth Surface Fifteenth Surface k 0.000000E+00  0.000000E+00 −4.798392E+01  1.339695E+00  0.000000E+00−1.400000E+01 −7.255015E+00 A4 −5.251721E−02  1.294752E−02  9.636233E−02 1.137084E−01 −3.293360E−03 −1.218901E−01 −6.616273E−02 A6

 4.594311E−02 −9.765239E−02 −1.769041E−01 −1.538280E−02  3.444754E−02

A8

 5.714307E−02  1.278926E−01

−6.410498E−03 −4.707460E−03 A10

−6.335983E−02

 1.042025E−03

A12 −2.917635E−02 −3.819357E−02  8.370375E−03

−1.382047E−04 −1.342127E−04 A14  1.001606E−02

−1.935078E−03

 7.891123E−06  1.292080E−05  1.244055E−05 A16 −1.944011E−03−2.448640E−03

−7.681241E−07 −7.041151E−07 A18  1.874418E−04  2.778323E−04−2.384180E−05 −4.048407E−05  1.717852E−07  2.592077E−08

A20

 1.215801E−06

−3.787567E−10

indicates data missing or illegible when filed

The imaging lens in Example 2 satisfies conditional expressions (1) to(19) as shown in Table 7.

FIG. 4 shows spherical aberration (mm), astigmatism (mm), and distortion(%) of the imaging lens in Example 2. As shown in FIG. 4, eachaberration is corrected excellently.

EXAMPLE 3

The basic lens data is shown below in Table 3.

TABLE 3 Example3 Unit mm f = 5.57 Fno = 1.60

ih = 4.60 TTL = 6.63 Surface Data i r d (Object) Infinity Infninity Ndvd  1(Stop) Infinity

 2* 2.2747

1.544 55.86 (vd1)  3*

 4* 3.0252 0.2700

 5* 2.3462 0.5418  6* 27.1497 0.5869 1.535 55.66 (vd3)  7* −20.14360.1483  8* Infinity 0.3688 1.671 19.48 (vd4)  9* Infinity 0.5800 10*−10.4391 0.4500

19.48 (vd5) 11*

0.0150 12* 3.0815 0.5312 1.544 55.86 (vd6) 13* 5.6215 0.4525 14* 3.59350.5501 1.535 55.66 (vd7) 15* 1.6820 0.5756 18 Infinity 0.2100 1.517

19 Infinity

Image Plane Constituient Lens Data Lens Start Surface Focal LengthComposite Focal Length Entrance pupil diameter 1  2  5.831 f34 21.718EPd 3.480 2  4 −18.526 3  6  21.718 4  8 Infinity 5 10 −81.213 6 12 11.750 7 14

Aspheric Surface Data Second Surface Third Surface Fourth Surface FifthSurface Sixth Surface Seventh Surface Eighth Surface k  0.000000E+00 0.000000E+00  0.000000E+00  0.000000E+00  0.0000000E+00  0.000000E+00−1.000000E+00 A4

−6.296515E−02 −1.043938E−01

 1.298295E−02 −6.469153E−02 −7.894430E−02 A6  2.807004E−02  5.762156E−02

−1.972043E−01  6.505569E−02  8.426743E−02 A8

−2.215031E−02 −6.760046E−02  1.893350E−01

A10  7.745134E−02 −1.227615E−02

 1.537755E−01

A12 −6.158931E−02  2.122712E−02 −7.428624E−02  3.309200E−01

−1.119775E−01 −1.548126E−01 A14

−1.271855E−02  5.458074E−02 −2.168383E−01 −1.134784E+00

 7.340315E−02 A16

−2.407215E−02  8.953511E−02  5.384557E−01

−2.051973E−02 A18  1.641318E−03

 5.756268E−03 −2.138379E−02 −1.422874E−01 −1.838203E−04  3.120139E−03A20 −1.229721E−04 4.664576E−05 −5.760383E−04  2.284517E−03

 1.521921E−04 −1.994003E−04 Ninth Surface Tenth Surface Eleventh SurfaceTwelth Surface Thirteenth Surface Fourteenth Surface Fifteenth Surface k−1.000000E+00  0.000000E+00  0.000000E+00

 0.000000E+00 −1.390000E+01 −5.542509E+00 A4

 1.641143E−02  2.604186E−03  2.717924E−02  7.201532E−02 −1.128539E−01

A6  5.475657E−02

A8

−5.487630E−02

 2.797158E−02 −1.219101E−02

A10  8.816247E−02  3.140474E−02

A12 −5.468971E−02 −1.115915E−02

−4.488244E−04 −3.765518E−04 A14  2.074135E−02

−1.398841E−04 −1.251662E−04  4.483359E−05  3.950262E−05 A16

−4.128323E−04

 7.561190E−06 −2.763660E−06 −2.531163E−06 A18  5.914835E−04 4.074587E−05  4.135877E−06 −4.377155E−07 −2.376997E−07

A20 −3.184344E−05 −1.791414E−06 −1.027388E−07  9.422799E−09

indicates data missing or illegible when filed

The imaging lens in Example 3 satisfies conditional expressions (1) to(19) as shown in Table 7.

FIG. 6 shows spherical aberration (mm), astigmatism (mm), and distortion(%) of the imaging lens in Example 3. As shown in FIG. 6, eachaberration is corrected excellently.

EXAMPLE 4

The basic lens data is shown below in Table 4.

TABLE 4 Example4 Unit mm f = 5.57 Fno = 1.60

ih = 4.60 TTL = 6.64 Surface Data i r d (Object) Infinity Infinity Nd vd 1 (Stop) Infinity

 2*  2.2837

1.544

 3*  7.1080 0.1103  4*  3.7117 0.3000 1.671 19.48 (vd2)  5*  2.77580.4805  6*

1.535 55.66 (vd3)  7* −21.5193 0.1681  8* Infinity 0.3573 1.671 19.48(vd4)  9* Infinity 0.5516 10*

0.4501 1.671 19.48 (vd5) 11* −16.5014 0.0150 12*

1.544 55.86 (vd6) 13*  5.5029 0.4272 14*  3.4841 0.6000 1.535 55.66(vd7) 15*

0.5756 18 Infinity 0.2100 1.517

19 Infinity 0.4542 Image Plane Constituent Lens Data Lens Start SurfaceFocal Length Composite Focal Length Entrance pupil diameter 1  2

f34

EPd

2  4 −18.821 3  6

4  8 Infinity 5 10 −67.775 6 12

7 14  −6.777 Aspheric Surface Data Second Surface Third Surface FourthSurface Fifth Surface Sixth Surface Seventh Surface Eighth Surface k 0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00 0.000000E+00 −1.000000E+00 A4

−9.057730E−02 −3.195637E−02  1.861620E−02 −6.510127E−02 −7.736654E−02 A6 3.878134E−02  2.426110E−02

−2.451460E−01  1.005281E−01  8.642745E−02 A8

 2.167883E−02 −2.847487E−02

A10  1.081452E−01 −4.871503E−02  3.320617E−02

 3.670115E−01

A12 −8.640736E−02

 7.757618E−01

−3.420808E−01 −1.732591E−01 A14  4.334337E−02

 4.501375E−02

A16

 3.027824E−01  7.204544E−01 −6.978192E−02

A18  2.280615E−03 −5.435228E−04

−8.482898E−02 −1.928556E−01  1.371166E−02  3.451035E−03 A20−1.681618E−04

 1.032983E−02

−1.151018E−03

Ninth Surface Tenth Surface Eleventh Surface Twelth Surface ThirteenthSurface Fourteenth Surface Fifteenth Surface k

 0.000000E+00  0.000000E+00 −6.360830E−01  0.000000E+00 −1.370000E+01−5.779678E+00 A4

 1.811107E−02  5.442346E−03  3.523355E−02  7.530750E−02 −1.056644E−01−6.716590E−02 A6  5.125329E−02  5.100828E−02  3.152321E−02

−7.455170E−02  3.507175E−02  2.191518E−02 A8

A10

 3.882039E−02  1.374358E−02

 2.042883E−03  1.324812E−03 A12

−1.232603E−02

 1.510065E−03  1.178265E−03

−2.055463E−04 A14

 2.067047E−03  5.152424E−04

 2.111140E−05 A16

−3.807930E−05

 6.747190E−06 −1.8480323E−06 −1.352829E−06 A18  6.508312E−04

 6.019542E−07 −3.140574E−07

 6.682421E−08

A20 −3.534829E−05  2.463874E−06  5.508754E−08  4.109735E−09 2.453352E−09

indicates data missing or illegible when filed

The imaging lens in Example 4 satisfies conditional expressions (1) to(19) as shown in Table 7.

FIG. 8 shows spherical aberration (mm), astigmatism (mm), and distortion(%) of the imaging lens in Example 4. As shown in FIG. 8, eachaberration is corrected excellently.

EXAMPLE 5

The basic lens data is shown below in Table 5.

TABLE 5 Example5 Unit mm f = 5.51 Fno = 1.40

ih = 4.60 TTL = 8.64 Surface Data i r d (Object) Infinity Infinity Nd vd 1 (Stop) Infinity

 2*  2.2624 1.1514 1.544 55.86 (vd1)  3*  5.8864 0.1157  4*  4.05510.3000 1.671 19.48 (vd2)  5*  3.3277

 6*  14.4417 0.5860 1.535 55.68 (vd3)  7*  35.9261 0.1168  8* Infinity0.3705

19.48 (vd4)  9* Infinity 0.4558 10*

0.5427 1.671 19.48 (vd5) 11* −28.1443

12*  4.4310 0.4500 1.544 55.86 (vd6) 13*  6.3517 0.3142 14*  3.31550.6000 1.535 55.66 (vd7) 15*  1.7171

18 Infinity 0.2100 1.517 64.20 19 Infinity 0.4239 Image PlaneConstituent Lens Data Lens Start Surface Focal Length Composite FocalLength Entrance pupil diameter 1  2  6.071 f34 44.730 EPd 3.938 2  4−33.116 3  6 44.730 4  8 Infinity 5 10 35.208 6 12 24.867 7 14 −7.662Aspheric Surface Data Second Surface Third Surface Fourth Surface FifthSurface Sixth Surface Seventh Surface Eighth Surface k  0.000000E+00 0.000000E+00  0.000000E+00  0.000000E+00  0.0000000E+00  0.000000E+00−1.000000E+00 A4 −7.045140E−03 −6.878454E−02

−3.683637E−02

−1.371583E−01

A6

 4.53359E−02

−1.238019E−01  3.425119E−01  4.005952E−01 A8

−6.313206E−02

 3.345272E−01  3.594223E−01 −6.490333E−01 −7.698873E−01 A10

−5.258138E−01 −6.316843E−01  7.222054E−01

A12  −5.23500E−03 −3.254229E−02  3.625737E−02  7.174857E−01 6.831755E−01 −4.815571E−01

A14  1.166328E−03

−1.700714E−02

 1.867817E−01  3.251018E−01 A16

−3.501523E−03  4.782678E−03

−9.321094E−02 A18

−7.358422E−04 −5.739409E−02 −4.439512E−02

 1.493275E−02 A20

 4.412688E−03  9.429185E−05 −1.028848E−03 Ninth Surface Tenth SurfaceEleventh Surface Twelth Surface Thirteenth Surface Fourteenth SurfaceFifteenth Surface k −1.000000E+00  0.000000E+00

 0.000000E+00 −9.700000E+00 −5.774181E+00 A4

−7.712794E−03

 8.211276E−02

A6

−3.366737E−02 −1.032339E−01 −8.991723E−02  5.333300E−02

A8

 2.177120E−02  1.000032E−01

−1.685013E−02

A10

−1.323166E−02 −3.921720E−02

A12 −1.053417E−01 −2.524223E−02  5.207883E−03

−4.837101E−04 −2.982715E−04 A14  3.793560E−02  6.718386E−03

 4.085274E−05

A16

 1.364542E−04

A18  9.970694E−04  1.113452E−04

−5.605832E−07

A20 −5.070235E−05 −4.727607E−06

−7.723804E−10 −8.437552E−10

indicates data missing or illegible when filed

The imaging lens in Example 5 satisfies conditional expressions (1) to(19) as shown in Table 7.

FIG. 10 shows spherical aberration (mm), astigmatism (mm), anddistortion (%) of the imaging lens in Example 5. As shown in FIG. 10,each aberration is corrected excellently.

EXAMPLE 6

The basic lens data is shown below in Table 6.

TABLE 6 Example6 Unit mm f = 5.57 Fno = 1.50

ih = 4.60 TTL = 6.64 Surface Data i r d (Object) Infinity Infinity Nd vd 1 (Stop) Infinity

 2*

1.0551 1.544 55.86 (vd1)  3*

0.0808  4*  4.3121 0.3000

 5*  3.4440 0.4635  6*  21.2163 0.6346 1.535 55.66 (vd3)  7*

0.1148  8* Infinity 0.3800 1.671 19.48 (vd4)  9* Infinity 0.5002 10*351.0886 0.4586 1.671 19.48 (vd5) 11* −31.3180 0.0150 12*  4.3525 0.54301.544 55.86 (vd6) 13*  6.3370 0.3740 14*

0.6003 1.535 55.66 (vd7) 15*

18 Infinity 0.2100 1.517

19 Infinity 0.4052 Image Plane Constituent Lens Data Lens Start SurfaceFocal Length Composite Focal Length Entrance pupil diameter 1  2

f34

EPd 3.714 2  4 −29.588 3  6  59.884 4  8 Infinity 5 10  42.848 6 12

7 14  −7.223 Aspheric Surface Data Second Surface Third Surface FourthSurface Fifth Surface Sixth Surface Seventh Surface Eighth Surface k 0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00

 0.000000E+00 −1.000000E+00 A4

−7.743333E−02 −1.074340E−01 −1.851354E−02

A6  2.179802E−02  7.844181E−02

−1.425778E−01

A8 −3.624435E−02

−3.494137E−02  5.332276E−01  4.706754E−01 −5.190534E−01

A10  3.480568E−02

 1.382178E−02

 6.351718E−01  5.716783E−01 A12

−1.200113E−02

 9.4884351−01

A14  6.502815E−03

 1.026891E−02 −8.635176E−01

 2.201743E−01  2.111154E−01 A16 −1.158161E−03 −4.958314E−03−4.882393E−03  3.926748E−01  2.918252E−01

A18  8.583353E−05

−1.003948E−01 −7.116327E−02  7.845120E−03  1.013186E−02 A20

−1.138530E−04

−3.779519E−04 −7.149110E−04 Ninth Surface Tenth Surface Eleventh SurfaceTwelth Surface Thirteenth Surface Fourteenth Surface Fifteenth Surface k−1.000000E+00  0.000000E+00 −2.396511E+01 −4.354261E−02  0.000000E+00−1.375000E+01

A4

 4.767572E−02

−1.094065E−01 −7.389445E−02 A6

−2.316436E−02

 3.994294E−02  2.796487E−02 A8 −1.828322E−01 −1.043287E−01

 9.883734E−02  2.758383E−02 −1.393856E−02

A10  1.824198E−01  6.387794E−02 −4.148750E−03 −4.224601E−02

 3.693571E−03

A12 −1.118280E−01 −2.422575E−02  2.496111E−03  1.191320E−02

A14  4.289138E−02

−8.195658E−04 −2.148317E−03 −7.057379E−05

 4.342979E−05 A16

−9.127438E−04  1.471886E−04  2.377587E−04  1.953010E−07

−2.746252E−06 A18  1.289809E−03

−1.384374E−05 −1.467551E−05  2.613763E−07  1.438553E−07

A20 −7.048303E−05

 3.858752E−07 −1.058867E−08 −2.182080E−09

indicates data missing or illegible when filed

The imaging lens in Example 6 satisfies conditional expressions (1) to(19) as shown in Table 7.

FIG. 12 shows spherical aberration (mm), astigmatism (mm), anddistortion (%) of the imaging lens in Example 6. As shown in FIG. 12,each aberration is corrected excellently.

In table 7, values of conditional expressions (1) to (19) related to theExamples 1 to 6 are shown.

TABLE 7 Confidential expression Example 1 Example 2 Example 3 Example 4Example 5 Example 6  (1) vd2 19.48 19.48 19.48 19.48 19.48 19.48  (2)vd3/vd6 2.86 2.86 2.86 2.86 2.86 2.86  (3) (T5/TTL) × 100 0.23 0.23 0.230.23 0.25 0.23  (4) vd4 55.86 19.48 19.48 19.48 19.48 19.48  (5) vd2/vd51.00 1.00 1.00 1.00 1.00 1.00  (6) vd3/vd6 1.00 1.00 1.00 1.00 1.00 1.00 (7) (D2/f2) × 100 −1.83 −1.57 −1.46 −1.59 −0.91 −1.01  (8) (D5/| f5 |4.36 3.82 0.55 0.86 1.54 1.07  (9) (T3/TTL) × 100 2.94 2.76 2.24 2.531.76 1.73 (10) |f3/f5| 1.37 1.29 0.27 0.34 1.27 1.40 (11) |f3/f7| 3.043.15 3.38 3.40 5.84 8.29 (12) r2/f 1.40 1.34 1.24 1.28 1.07 1.16 (13)r10/f −1.04 −1.05 −2.36 −2.96 −5.10 −5.62 (14) r13/f 0.99 1.02 0.65 0.630.60 0.67 (15) r5/f 1.65 1.88 4.88 5.12 2.62 3.81 (16) r14/f 0.36 0.360.30 0.30 0.31 0.32 (17) f34/f 3.45 3.49 3.90 4.14 8.11 10.75 (18)(D3/f3) × 100 2.57 2.54 2.75 2.59 1.31 1.06 (19) TTL/EPd 1.78 1.78 1.901.91 1.69 1.79

When the imaging lens according to the present invention is adopted to aproduct with the camera function, there is realized contribution to thewide field of view, the low-profileness and the low F-number of thecamera and also high performance thereof.

DESCRIPTION OF REFERENCE NUMERALS

-   ST: aperture stop-   L1: first lens-   L2: second lens-   L3: third lens-   L4: fourth lens-   L5: fifth lens-   L6: sixth lens-   L7: seventh lens-   ih: maximum image height-   IR: filter-   IMG: imaging plane

What is claimed is:
 1. An imaging lens comprising in order from anobject side to an image side, a first lens with positive refractivepower having an object-side surface being convex in a paraxial region, asecond lens with negative refractive power in a paraxial region, a thirdlens, a fourth lens being a double-sided aspheric lens, a fifth lens, asixth lens having an image-side surface being concave in a paraxialregion, and a seventh lens with negative refractive power having animage-side surface being concave in a paraxial region, wherein theimage-side surface of said seventh lens is an aspheric surface having atleast one pole point in a position off the optical axis, and followingconditional expressions (1), (2) and (3) are satisfied:10.00<vd2<29.00  (1)1.80<vd3/vd5<4.00  (2)0.10<(T5/TTL)×100<0.40  (3) where vd2: an abbe number at d-ray of thesecond lens, vd3: an abbe number at d-ray of the third lens, vd5: anabbe number at d-ray of the fifth lens, T5: a distance along the opticalaxis from an image-side surface of the fifth lens to an object-sidesurface of the sixth lens, and TTL: a total track length.
 2. The imaginglens according to claim 1, wherein an object-side surface of said thirdlens is convex in a paraxial region.
 3. The imaging lens according toclaim 1, wherein an object-side surface of said seventh lens is convexin a paraxial region.
 4. The imaging lens according to claim 1, whereinan object-side surface and an image-side surface of said fourth lens areplane surfaces in a paraxial region.
 5. The imaging lens according toclaim 1, wherein the following conditional expression (6) is satisfied:0.60<vd3/vd6<1.40  (6) where vd3: an abbe number at d-ray of the thirdlens, and vd6: an abbe number at d-ray of the sixth lens.
 6. The imaginglens according to claim 1, wherein the following conditional expression(8) is satisfied:0.30<(D5/|f5|)×100<6.50  (8) where D5: a thickness along the opticalaxis of the fifth lens, and f5: a focal length of the fifth lens.
 7. Theimaging lens according to claim 1, wherein the following conditionalexpression (10) is satisfied:0.10<|f3/f5|<2.10  (10) where f3: a focal length of the third lens, andf5: a focal length of the fifth lens.
 8. The imaging lens according toclaim 1, wherein the following conditional expression (12) is satisfied:0.50<r2/f<2.10  (12) where r2: a paraxial curvature radius of animage-side surface of the first lens, and f: a focal length of theoverall optical system of the imaging lens.
 9. The imaging lensaccording to claim 1, wherein the following conditional expression (13)is satisfied:−8.50<r10/f<−0.70  (13) where r10: a paraxial curvature radius of animage-side surface of the fifth lens, and f: a focal length of theoverall optical system of the imaging lens.
 10. The imaging lensaccording to claim 1, wherein the following conditional expression (14)is satisfied:0.30<r13/f<1.55  (14) where r13: a paraxial curvature radius of anobject-side surface of the seventh lens, and f: a focal length of theoverall optical system of the imaging lens.
 11. An imaging lenscomprising in order from an object side to an image side, a first lenswith positive refractive power having an object-side surface beingconvex in a paraxial region, a second lens with negative refractivepower in a paraxial region, a third lens, a fourth lens being adouble-sided aspheric lens, a fifth lens, a sixth lens having animage-side surface being concave in a paraxial region, and a seventhlens with negative refractive power having an image-side surface beingconcave in a paraxial region, wherein the image-side surface of saidseventh lens is an aspheric surface having at least one pole point in aposition off the optical axis, an image-side surface of said first lensis concave in a paraxial region, said third lens is formed in a meniscusshape in a paraxial region, an image-side surface of said fifth lens isconvex in a paraxial region, an object-side surface of said seventh lensis convex in a paraxial region, and the following conditionalexpressions (2) and (4) are satisfied:1.80<vd3/vd5<4.00  (2)10.00<vd4<29.00  (4) where vd3: an abbe number at d-ray of the thirdlens, vd5: an abbe number at d-ray of the fifth lens, and vd4: an abbenumber at d-ray of the fourth lens.
 12. The imaging lens according toclaim 11, wherein the following conditional expression (3) is satisfied:0.10<(T5/TTL)×100<0.40  (3) where T5: a distance along the optical axisfrom an image-side surface of the fifth lens to an object-side surfaceof the sixth lens, and TTL: a total track length.
 13. The imaging lensaccording to claim 11, wherein an object-side surface and an image-sidesurface of said fourth lens are plane surfaces in a paraxial region. 14.The imaging lens according to claim 11, wherein the followingconditional expression (5) is satisfied:0.60<vd2/vd5<1.40  (5) where vd2: an abbe number at d-ray of the secondlens, and vd5: an abbe number at d-ray of the fifth lens.
 15. Theimaging lens according to claim 11, wherein the following conditionalexpression (7) is satisfied:−2.30<(D2/f2)×100<−0.50  (7) where D2: a thickness along the opticalaxis of the second lens, and f2: a focal length of the second lens. 16.The imaging lens according to claim 11, wherein the followingconditional expression (8) is satisfied:0.30<(D5/|f5|)×100<6.50  (8) where D5: a thickness along the opticalaxis of the fifth lens, and f5: a focal length of the fifth lens. 17.The imaging lens according to claim 11, wherein the followingconditional expression (9) is satisfied:1.00<(T3/TTL)×100<4.00  (9) where T3: a distance along the optical axisfrom an image-side surface of the third lens to an object-side surfaceof the fourth lens, and TTL: a total track length.
 18. The imaging lensaccording to claim 11, wherein the following conditional expression (11)is satisfied:1.55<|f3/f7|<12.50  (11) where f3: a focal length of the third lens, andf7: a focal length of the seventh lens.
 19. The imaging lens accordingto claim 11, wherein the following conditional expression (12) issatisfied:0.50<r2/f<2.10  (12) where r2: a paraxial curvature radius of animage-side surface of the first lens, and f: a focal length of theoverall optical system of the imaging lens.
 20. The imaging lensaccording to claim 11, wherein the following conditional expression (13)is satisfied:−8.50<r10/f<−0.70  (13) where r10: a paraxial curvature radius of animage-side surface of the fifth lens, and f: a focal length of theoverall optical system of the imaging lens.